Materials which undergo a change in their spatial extent when exposed to a specific applied electric field, i.e. materials which have piezoelectric properties, are used, for example, in actuators. For this use, high elongations of the material are desired as a response to the applied electric field. The achievable elongation of the materials is limited by their dielectric strength. In addition, conventional piezoelectric materials have a high lead content, which is harmful to people and the environment.